package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {


    @Value("${reggie.path}")
    private String basePath;


    /**
     * 文件上传
     * 参数file名字一定要跟页面上的payload中FormData的name键对应的值一致
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){

        log.info(file.toString());
        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        //截取原始文件名后缀
        String suffer = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID生成32位文件名，再拼接原始文件名后缀,防止文件名重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffer;
        //创建一个目录对象
        File dir = new File(basePath);
        if (!dir.exists()){
            //目录不存在，要先进行创建文件夹
            //否则直接上传文件会报错
            dir.mkdirs();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }


    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        FileInputStream fileInputStream = null;
        ServletOutputStream outputStream = null;
        try {
            //输入流，通过输入流读取文件内容
            fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            outputStream = response.getOutputStream();

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            outputStream.close();
            fileInputStream.close();
        }

    }
}
